MOEPHOLOGY AND EVOLUTION
Anthropoids they open at the apex of a triangular fold of mucous membrane, to which Pocock applied the name of frenal lamellae.
The arterial and nervous supply, and the venous drainage of the salivary glands are similar in the Apes and Man, but Man has more lymphatic glands in the neighbourhood of the salivary glands.
In the Chimpanzee the liver resembles that in Man. The umbilical fissure is much bridged over, and the fissure of the vena cava is also enclosed. Indications of lateral fissures exist. Near the umbilical region of the right lobe there is a small lobule directed ventrally. The gall-bladder is superficial and extends beyond the ventral margin of the lobe and it is flexed on itself. In occasional specimens the gall-bladder is deeply embedded in the liver substance. The Spigelian lobe is subquadrate, and the caudate lobe is a triangular cone directed to the right. In some specimens the apex of the caudate lobe reaches the right margin of the liver, but in others it does not do so. The relative sizes of the hepatic lobes may be expressed by Garrod's method thus:—
E-2 > L > Sp = C.
In the Orang the umbilical vein divides the liver info two halves, and there is no trace of lateral fissures. The umbilical fissure is bridged over, but the vena cava is not enclosed. The left lobe is fiat, expanded and nearly semicircular; but the right lobe is thick and oblong. The Spigelian lobe has a tongue-shaped process which overhangs the portal fissure, and the caudate lobe is well